14 - Studia Geobotanica. An international journal - Vol. 14 (1994)

THE SCHOENUS NIGRICANS COMMUNITIES OF CARICION DAVALLIANAE KLIKA 1934 IN THE EASTERN PO PLAIN (VENETO - FRIULI). The authors give a syntaxonomic revision of the Schoenus nigricans communities belonging to the Caricion davallianae Klika 1934 in the eastem Po Plain. On the basis of relevés from the literature and of originai ones a single association has been recognized. It joins the Erucastro-Schoenetum nigricantis Poldini 1972 and the Euphrasio marchesettii-Schoenetum nigricantis Marchiori & Sburlino 1982. The name of this association is Erucastro-Schoenetum nigricantis Poldini 1973 em. Sburlino & Ghirelli. Two subassociations have been recognized: Erucasrro-Schoenetyn nigricantis typicum and Erucastro-Schoenetum nigricantis scorzonererosum humilis subass. nova.

A pollen analysis of Genisia sect. Spartocarpus has been carried out on 124 samples from 15 species. The taxa were compared in terms of quantitative and qualitative pollen characters, analysed by LM and SEM. Multivariate analysis subdivides taxa into four clusters. Genisia radiala, G. holopeiala and G. hassertiana, E-Alpine-Balkanic species with capitate inflorescence, form an isolate cluster that is palynologically, morphologically and karyologically homogeneous. The other species, with inflorescences of racemous type, can be grouped in three clusters: the first comprising G. sessilifolia, G. nissana and G. aucheri, Balkan-Anatolian taxa, the second including G. spartioides, G. hoenseleri and G. numidica. Spanish and N-African species, the third comprising the W-Mediterranean G. ephedroides, G. Ihyrrena, G. gasparrinii, G. cilentina, G. aetnensis and G. dorycnifolia. Pollen characters and morphological, karyological ancl biogeographical data appear to be related. The arrangement proposed by Gibbs (1966), who has grouped all the examined species in sect. Spartocarpus, is supported by the pollen analysis. On the basis of pollen characters all taxa of Genista sect. Spartocarpus may be considered as well distinguished. The specific treatment of these taxa in Greuter et al. (1989) is, in generai terms, confined by palynological data. However. the grouping of G. radiata. G. holopetala and G. hassertiana in the G. radiata-group and of G. ephedroides. G. gasparrinii. G. Ihyrrena and G. cilentina in lhe G. ephedroides-group is proposed.

A karyological analysis of the two species of Sparrocyrisus (S. filipes and S. supranubius) was carried out. Both species have the same chromosome nunber 2n=4S. S. nubigenus shows a number of accessory chromosomes varying from O to 4, with a maximum frequency of 2. In addition a comparison was made with the karyological data already available for the taxa of the Cytisus-group and for other intermediate genera of the Genisteae.

Seventy-five infrageneric taxa of lichens are reported from the Dolomites (NE Italy, Tre Cime di Lavaredo). The samples were collected in two stations, one in the Alpine belt (2300-2400 rn), the other in the subalpine belt (1800m). Seventeen taxa are new to the Region of Veneto; eight of these are also new lo the lichen flora of ltaly: these are: Caloplaca isidiigera Vezda, Candelariella unilocularis (Elenk.) comb. nov., Candelariella plumbea Poelt & Vezda. Eiglera homalomorpha (Nyl.) Clauz. & Roux, Farnoldia jurana ssp. bicincta (Hertel) Clauz. & Roux, Lecanora meolansii B. de Lesd., Verrucaria zamenhofiana Clauz. & Roux., Xanthoria elegans v. orbicularis (Schaerer) Clauz. & Roux.

ON THE CALCICOLOUS LICHEN COMMMUNITIES FROM COASTAL AREAS 0F THE SOUTHERN IBERIAN PENINSULA AND MOROCCO. The calcicolous lichen vegetation along the coasts of southern Spain, Portugal and Morocco was investigated. On the basis of the phytosociological approach the following associations and communities are recognized: Caloplacetum subochraceae, Verrucarietum cazzae, community of Solenopsora cesatii and S. olivacea var. olivacea, community of Rinodina immersa, community of Aspicilia calcarea and Xanthoria calcicola, Dirinetum repandae, Opheographetum durieui, community of Heppia solorinoides and Psora vallesiaca, community of Xanthoria resendei and community of Caloplaca xantholyta and Lepraria nivalis. The ecology. distribution and floristic composition of all syntaxonomic units are discussed.